title: Nutritional factors and preservation of C-peptide in youth with recently diagnosed type 1 diabetes: SEARCH Nutrition Ancillary Study.
abstract: OBJECTIVE
  To test the novel hypothesis that nutritional factors previously associated with type 1 diabetes etiology or with insulin secretion are prospectively associated with fasting C-peptide (FCP) concentration among youth recently diagnosed with type 1 diabetes.
  
  
  METHODS
  Included were 1,316 youth with autoantibody-positive type 1 diabetes who participated in the SEARCH for Diabetes in Youth study (baseline disease duration, 9.9 months; SD, 6.3). Nutritional exposures included breastfeeding and age at introduction of complementary foods, baseline plasma long-chain omega-3 fatty acids including eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), vitamin D, vitamin E, and, from a baseline food frequency questionnaire, estimated intake of the branched-chain amino acid leucine and total carbohydrate. Multiple linear regression models were conducted to relate each nutritional factor to baseline FCP adjusted for demographics, disease-related factors, and other confounders. Prospective analyses included the subset of participants with preserved β-cell function at baseline (baseline FCP ≥0.23 ng/mL) with additional adjustment for baseline FCP and time (mean follow-up, 24.3 months; SD, 8.2; n = 656). FCP concentration was analyzed as log(FCP).
  
  
  RESULTS
  In adjusted prospective analyses, baseline EPA (P = 0.02), EPA plus DHA (P = 0.03), and leucine (P = 0.03) were each associated positively and significantly with FCP at follow-up. Vitamin D was unexpectedly inversely associated with FCP (P = 0.002).
  
  
  CONCLUSIONS
  Increased intake of branched-chain amino acids and long-chain omega-3 fatty acids may support preservation of β-cell function. This represents a new direction for research to improve prognosis for type 1 diabetes.
authors.affiliation: Department of Nutrition, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA. ejmayer-davis@unc.edu
authors.forename: Elizabeth J
authors.initials: EJ
authors.lastname: Mayer-Davis
authors.forename: Dana
authors.initials: D
authors.lastname: Dabelea
authors.forename: Jamie L
authors.initials: JL
authors.lastname: Crandell
authors.forename: Tessa
authors.initials: T
authors.lastname: Crume
authors.forename: Ralph B
authors.initials: RB
authors.lastname: D'Agostino
authors.forename: Lawrence
authors.initials: L
authors.lastname: Dolan
authors.forename: Irena B
authors.initials: IB
authors.lastname: King
authors.forename: Jean M
authors.initials: JM
authors.lastname: Lawrence
authors.forename: Jill M
authors.initials: JM
authors.lastname: Norris
authors.forename: Catherine
authors.initials: C
authors.lastname: Pihoker
authors.forename: Natalie
authors.initials: N
authors.lastname: The
mesh_terms: D000293:Adolescent; D000597:Amino Acids, Branched-Chain / Q000008:administration & dosage; D002096:C-Peptide / Q000097:blood*; D002648:Child; D003922:Diabetes Mellitus, Type 1 / Q000097:blood*; D004281:Docosahexaenoic Acids / Q000008:administration & dosage; D015118:Eicosapentaenoic Acid / Q000008:administration & dosage; D005215:Fasting / Q000097:blood; D015525:Fatty Acids, Omega-3 / Q000008:administration & dosage; D005260:Female; D006801:Humans; D008297:Male; D009752:Nutritional Status; D011446:Prospective Studies; D014481:United States
chemical_list: D000597:Amino Acids, Branched-Chain; D002096:C-Peptide; D015525:Fatty Acids, Omega-3; D004281:Docosahexaenoic Acids; D015118:Eicosapentaenoic Acid